These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
Nightmare Fuel: Getting there by the first chapter after the prologue. "Zirah would kill a baby just to stop him crying"... made even worse because he still suffers from Cuteness Proximity. It's just creepy.
"Creepy" sells Zirah a million miles short of the pants-wetting, throat-constricting, limb-trembling horror that he is capable of.
Tear Jerker: Seriously, this story WILL reduce you to a sobbing wreck.
The Woobie: Caphriel.Ok, he's generally pretty stoic about it, but read that last chapter and tell me you don't want to give him a hug, thank him for everything he's done, and let Canon!Aziraphale fuss over him for a while.